Conventional methods of packing often include surrounding an object within a packing container by a quantity of loose-fill packing material. Loose-fill packing material is generally a pourable material which is stored in a large overhead container or hopper and directed into packing containers by a flexible chute. Once in place around an object, the material provides sufficient support to resist migration of the object within the packing container. Probably the most important characteristic of a loose-fill packing material is its ability to repeatedly absorb impact energy without being permanently deformed or crushed. Loose-fill packing material must also be relatively light to minimize shipping costs.
The most convenient and commonly used loose-fill packing material has been expanded polystyrene, often referred to as synthetic "popcorn." Expanded polystyrene and other such foam-type materials are light, provide a high degree of impact energy absorption, and are easily and conveniently formed in a variety of shapes.
However, expanded polystyrene and many polystyrene substitutes also have a significant disadvantage in that they are not biodegradable. As concern has increased over waste disposal and its impact on the environment, this disadvantage has gained considerable social and economic importance.
A number of alternative, biodegradable packing materials have been suggested. One of the most interesting of these alternatives is actual popped corn kernels. Unfortunately, the biodegradable alternatives have generally been unacceptable. The primary shortcoming of many such packing materials is their lack of sufficient impact energy absorption. Many packing materials also fail to prevent migration of objects within a packing container or to provide sufficient support for the objects. Such materials are also often costly, relatively heavy, and are difficult or inconvenient to work with.